Electric circuit installation



Aug.3o,1932. M w, MC'ARDLE C 1,875,018

ELECTRIC CIRCUIT INSTALLATION Filed Jly 19,'1950 2 sheets-sheet 1 Aug. 30, 1932. M. w. MCARDLE ELECTRIC CIRCUIT INSTALLATION 2 sheets-sheet 2 Filed July 19, 1930 um 55 Hfen/@ys Patented Aug.. 30, 1932 UNITED STATES PATENT ori-ic MICHAEL W. MGABDLE, OF CHICAGO, ILLINOIS ELECTRIC CIRCUIT INSTALLATION Application led July 19, 1930. Serial No. 469,108.

J. In the drawings:

Figure 1 is a perspective view of a casing constituting one element of the invention, sai casing being adapted to be mounted upon the wall of the building or apartment served fory receiving the contact carrier which constitutes the remainder of the invention.

Figure 2 is a section at the line 2-2 on Figure 1.

Figure 3 is a transverse section on an enr-` larged scale of one of the conductive strips constituting the circuit member in the casing with its insulating support.

Figure 4 is a section at the line 4-4 on Figure 3.

Figure 5 is a perspective View of a short piece of the conductive strip constituting the circuit element carried by the casing as prepared for mounting in the casing, the same being shown attached to its insulating support.

Figure 6 is a tact carrier.

Figure 7 is a section transverse with respect to the casing showing the contact carrier in side elevation engaged in circuit-connecting position iii the casing.

Figure 8 is an axial section ofthe Contact carrier in the plane of the section of Figure 7.

Figure 9-is an outer end elevation of the perspective view of the con- Same.

Figure 10 is a detail section at the line 10-10 on Figure 9.

4Figure 11 is a view similar to Figure 7 showing a modification of the casing.

Figure 12 is a detail section similar to part of Figure 11 showing a slight further modification.

Referring to the drawings:

The casing, which may be referred to as a structural molding, identified in its entirety as a casing, A, and which, in the, particular latter by lugs,

form shown, is adapted to be mounted upon the upper edge of the base board of an apartment, comprises a back or base member, 10, and two cooperating front members 12, 12. The base member is a strip of normally nonconductive material, as wood, having a plane fiat forward face, as seen at 11, and the coo erating members, 12, 12, each consists of a p ane strip rabbeted at one side and edge, as indicated at 13, the two strips being mounted upon the plane face, 11, of the base member with their rabbets facing each other and inwardly, and their proximate longitudinai edges, 14,14, spaced apart narrowly to form a slot, 15. Onthe inner rabbeted faces of the members, 12, and thereby at opposite sides of the slot, there are mounted conducting stripsnl, each of which is prepared for suc mounting b being first mounted upon an in- .sulating strip, 17, the manner of such mount` ing being hereinafter specifically described.

The de th of the rabbets is sufficient to leave a su tantial interval between the conductive strip mounted upon the inner face of the rabbet and the opposite flat face, 11, of the base, 10.

.The insulating strips, 17, are several times wider than the conductive strips, 16, which are in ounted upon them, so that there is a substantial margin of the insulating strips at both sides of the conductive strip, as indicated at 19, 19. The conductive strip is secured to the insulating strip so as to be retained about midway in the width of the 20, 20, struck from the conductive strip and protruded through the in sulating strip and clinched down upon the latter on the opposite side thereof from the conductive strip, as seen in Figure 3.

For 'insulatingly covering the clinched safely` described, might be terial which is secured which the lugs are covered, are mounted and secured as described, upon the inner rab- -beted faces of the casing members, 12, 12,

with the fold of the insulation constituting the edge which is toward the slot.

The insulating strips are made of suitably thin sheet material of suitable texture to be readily punctured by the clinching lugs, 20, as illustrated in Figures 3, 4 and 5, and suitably tough and flexible to be. folded, as illustrated in Figure 3 to form of an integral strip the insulation for carrying the conductive strip and the insulation for covering the clinching 1u s.

glhe reason for preferably making the two insulation strips unitary, and folding the unitary strip as described for covering the lugs, is chiefly to avoid presenting at the slot two edges of strips terminals of the contact carrier, hereinafter entered instead of entering behind the conducting strips for the purpose of contact therewith, as will be understood from the hereinafter contained description of the contact carrier and contact terminals thereof.

The contact carrier, identiied in entirety as the carrier, B, comprises a body member, 30, of non-conductive material preferably cylindrical, as shown, and having two parallel longitudinally extending apertures, 31, 31, for receiving two electrically conductive strips, 40, 40, hereinafter called contacts, and admitting alongside them respectively in the'respective apertures the terminal contacts of circuit-connecting plugs of usual form and dimensions.

The contacts, 40, 40, are insulated from each other by the substance of the body member intervening between the longitudinal extent of the apertures, 31, 31, and at the parts of said contacts which extend from said apertures as hereinafter particularly described, by a thin narrow strip, 32, of insulating marigidly in the body member between the apertures, 31, 31, and projects longitudinally of the body member between the projecting and protruding portions of the contacts, 40, 40, which are iiexed as seen at 41 and 42 to offset their projecting portions, 43, 43, laterally toward each other,

and form shoulders, 44, 44, which stopl against the end of the body member between the apertures, 31, 31, at opposite 4sides of the projecting insulating strip, 32. The body member, 30', is furnished with a vterminal disk, 35, of insulating material having an aperture, 36. to accommodate the projecting portions, 43, 43, of the contacts, 40, 40, and the intervening projecting insulating strip, 32. This terminal disk is made fast to the body between which the Contact' member b two screws, 37, 37, as seen in Figures 7 an 10.

The contact carrier comprises in addition to the body member which may be understood as compr1singthe terminal disk, 35, a head, 38, which, as illustrated, is a disk of insulatmg materlal dimensionally mated with the terminal disk, 35, and attached to the body member by two bolts, 39, 39, which are set through suitable lon itudinally extending holes, 45, 45, in the bol y member and its terminal disk, said holes being bored of diameter to admit the bolts, and counterbored from the outer end to admit the heads of the bolts to a stop shoulder, 45, formed by the counterbore, and counterbored from the other end to admit coil springs, 50, around the bolts to the stop shoulder, 45", formed by the second' oounterbore.

The coil springs, 50, stopped, as described, at the inner ends on the stop shoulders, 45", react at their outer ends on the head disk, 45, into which the bolts are screwed for attaching the head to the body, adapted to be normally spaced from the end of the body a distance determined by the position of the stop shoulder, 45, the springsfoperating by their reaction as described, for holding the head,

38, yieldingly spaced the predetermined distance from the end of the body.

The head, 38, is centrally apertured to permit the contacts and intervening strip to protrude through said head; and at the protruding part the contacts are iiexed transversely in opposite directions away from each other, forming oppositely projecting terminals, 40*, 40, which are ali ed with each other and insulated from eac other by the interposed insulating strip, 32, the resulting form of the contact element being hereinafter referred to as Tform. The oppositely extending parts of the cross of the ing insulated from each other for contacting respectively the conductive strips, 16, 16, said conductive strips are also insulated from each other in the casing, as above described.

From the foregoing description it may be understood that for connecting the circuit which comprises the conductive strips mounted as described in the casing, A, the T-form T-form be? contact element ofy the contact carrier, B, is

tive strips, 16; and then the carrier being rotated 90 degrees, turning the contact terminals into position crosswise of said strips, respectively, and the pressure being released, the reaction of the spring, 50, stresses and holds the contacts on the conductive strips, malntaming the circuit connection, while the carrier may be shifted along the slot to any desired position in the length of the casing.

It will be understood that the conductive strips are connected to an electric circuit containing a source of current, as indicated conventionally at 60, 60.

In Figure 11, the front casing members are shown in a form somewhat preferred. In this form these casing members are shown with the edge of the rabbet toward the slot furnished with an inwardly projecting lip, 141, of sufficient Width to guard the edge of the insulation strip and the conductive strip which it carries from edgewise encounter with the contact terminal when the operator happens to prematurely turn the contact carrier or plug before it is pressedA inwardly to the limit so as to enterlsafely behind the conductive strip.

In Figure 1Q. there is shown a further detail modification of this lip construction for guarding against the liability of deforming or breaking the contact terminal by the premature turning of the contact carrier, the lip, 14", being for this purpose beveled, as seen at 14V, the bevel, preferably as shown. extending nearly to the corner which defines the side of the slot. thus making the bevel not merely a bevel of the lip, 14X, but a bevel of the rabbeted edge of the .casing member which forms one side of the slot. In order that the lip may be wide enough to guard not only against edgewise encounter of the contact terminal with the insulation strip, but also against edgewise contact with the conductive strip, and at the same time ensure that the contact terminals shall make proper conductive contact with the surface of the conductive strip, it is of advantage to form the contact terminals as shown in Figure 12, slightly flexed back at the ends, as seen air-10m.

I claim:

1. In a construction for the purpose indicated, in combination with a structural molding having a longitudinal cavity for accommodating the Wires of an electric circuit, an insulating strip and a conductive strip, the insulating strip being of penetrable material the conductive strip being secured to the insulating strip by securements extending from the latter through the former and clinched over ontov the insulating strip at the opposite side thereof from the conductive strip, and a second insulating` strip dimensionally mated to the first and applied to the first at the side at which said securements are clinched and secured to said first strip at the lateral margins of the two mated strips constituting the excess of width of the insulation strips over the conductive strip.

2. In a construction for the purpose indicated, in combination with a structural molding having a longitudinal cavity for accommodating the wires of an electric circuit,

an insulating strip and a conductive strip, the insulating strip being penetrable and liexible for folding upon itself the conductive strip secured to the insulation strip by securements extending from the latter through the former and clinched over onto the insulating strip at the opposie side thereof from the conductive strip, the insulating strip being wider than the conductive strip to afford substantial lateral margins at both sides of the conductive strip and to comprise at one side a width for forming a covering strip by folding longitudinally to lap onehalf the width over the other half thereby covering the clinched securements.

3. An article of manufacture for the purpose indicated consisting of a longitudinally hollow casing comprising a flat faced bar adapted to serve as an element of the interior finish of an apartment wall, and a pair of cooperating bars each longitudinally rabbeted mounted on said flat face of the first mentioned bar with their rabbets facing each other and the flat face of the first mentioned bar, and with the proximate edges of said rabbeted bars spaced apart to form a relatively narrow longitudinally extending slot communicating'with the longitudinal channel defined by the flat face of the first mentioned bar and the rabbets ofthe rabbeted bars; a pair of electrically conductive strips and insulating strips on which they are respectively mounted, said conductive strips being mounted by means of the insulating strips in the rabbets of said rabbeted bars respectively, whereby they are exposed for circuit connection in the longitudinal chan- 'nel mentioned at opposite sides of the longitudinal slot mentioned, the conductive strip being secured to the insulating strip by securing lugs struck from the conductive stri and penetrating the insulating strip an clinched down on the opposite side of the latter, and a second insulating strip applied to the first at the side opposite the conductive strip for insulating the clinching lugs. In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 17th day of July, 1930.

'MICHAEL W. MCARDLE. 

